HashMap我在 FX 程序的啟動(dòng)方法中暫時(shí)顯示信息時(shí)遇到問(wèn)題。public class stack extends Application{    String mCurrentLocation; // Store current location    // Map to store name as keys and easting and northing as values    HashMap<String, List <Double>> dict = new HashMap<>();    public static void main(String[] args) {        stack mainObject = new stack();        mainObject.run();// Method where the program is built        launch(args);    }    public void start(Stage primaryStage) throws Exception{        System.out.println("In in startFX: "); // debugging only        System.out.println(dict);           // debugging only        // More fx code    }    private void run(){        System.out.println("In main");        System.out.println(dict);        //Read Northing and Easting input received from a txt file        try{            Scanner scanner = new Scanner(new             File("NorthingAndEastings.txt"));            while(scanner.hasNext()){                List<Double> coordinates = new ArrayList<>();                String name = scanner.next(); // key                Double easting = scanner.nextDouble();                coordinates.add(easting); // list(0)                Double northing = scanner.nextDouble();                coordinates.add(northing); //list(1)                this.dict.put(name, coordinates);             }        scanner.close();        } catch(FileNotFoundException e){            System.out.println("Sorry, could not open"             + "'NorthingAndEastings.txt' for reading. Stopping");            System.exit(-1);        }        // For debugging only        for (Map.Entry me : dict.entrySet()){            System.out.println("Name: "+me.getKey() + " Loc: " +                          me.getValue());        }    }}在run()首先在 main 中調(diào)用的方法中，HashMap成員變量是從文本文件中填充的。但是當(dāng)代碼轉(zhuǎn)到我想顯示HashMap項(xiàng)目的 FX 時(shí)，字典是空的。我得到{};